The invention relates to a curtain comprising a web of temperature resistant material forming a web surface and having lateral edge regions on either side, which web may be wound onto and unwound from a coil arranged on a coil core having two ends and being supported by a bearing arrangement including at least one supporting surface. If, in this context, the term xe2x80x9ctemperature resistantxe2x80x9d is used, the degree of any temperature resistance will depend, also on the other fire protection measures discussed later in connection with the curtain, which can render a higher degree of temperature resistance superfluous.
In case of a fire, a dangerous element is constituted by the flames and the relatively high temperatures themselves. Simultaneously, there is also another potential danger from developing fumes or smoke having, certainly, also a higher temperature which, however, will not be as high as that of the blaze""s source. This smoke, which, due to its higher temperature, will generally pass through the upper regions of a room, has the tendency to spread in large rooms and to cool down on cooler walls. Then it will fill also the lower regions of the room so as to deprive people and animals as well of breath.
Therefore, an endeavor has to be to prevent the smoke from spreading and to draw it off in such a manner that it no longer constitutes a hazard for breathing air in lower regions of a room. Admittedly, an arrangement to provide surfaces for drawing off or blocking the smoke is difficult, because such surfaces should not obstruct the normal use of a room.
From DE-A-23 38 352, a curtain with the characteristics of the introductory part of claim 1 is known by which draw off surfaces without any obstruction are provided, such surfaces being optionally adapted to shield against a blaze (fire-resistance). A disadvantage of this known attempt resides in that the curtains, by virtue of their support and by the arrangement of loose webs which are movable relatively to each other, are difficult to maintain in tight condition so that they do not result in effectively drawing off or shielding in case of a fire with the resulting air current developing thereby.
Therefore, it is an object of the invention to provide a better and more secure guiding of the curtain, by which a deformation of the curtain in the manner of a wind-blown sail or forcing it out of its position by a strong air current is avoided. According to the invention, this object is achieved by designing the curtain with the coil core, at least on one of its ends, being supported adjustably in height within a guidance and/or the curtain is guided by lateral guide bars including an arrangement for preventing the inserted curtain edge to be drawn out and/or that at least two curtain webs the surfaces of which face each other have a common end bar forming a weight for the curtain.
If one considers the support of the coil at the upper end of a curtain and the end bar at the lower end thereof as a guide, in the broadest sense of this term, the concept of the present invention consists in general terms in providing a guidance to at least one of the ends or edges of a curtain so as to maintain the curtain tight in a planar configuration without bulging or flapping even with a strong air current during a blaze. The temperature-resistive materials mentioned in the claim may be formed by thin metal sheets as well as by fabrics, particularly by woven clothing, made of temperature-resistive materials, preferably glass fibers, but also from carbon fibers, polycarbon fibers or ceramic fibers. A preferred embodiment will be described later.
The problem with large widths of a web resides, of course, in the coil core""s bending. Since, however, the curtain will suitably be uninterrupted and continuous with adjacent mutually interconnected webs, the accommodation of an intermediate support is difficult, but is achieved by the invention.
A support will preferably be arranged at one of the edge regions, i.e. at those places where either two strips of web are situated edge by edge and/or where a free edge of the curtain is located. In this way, the web can be wound in a more tightened fashion resulting in less problems.
With the inventive design, it is easier to minimize or reduce actuation means for moving the curtain, i.e. only a single device will normally be necessary, e.g. a single motor rotating the coil.
For better guiding and for holding the curtain in a more tightened fashion, it is convenient to provide lateral guide bars, e.g. for large-area subdivision of a room by a curtain according to the invention.
In this way, a further problem can be under control. For the curtains are, of course, easily displaced out of their desired position by the air current developing during a fire, whereby sealing and. proper draw off of fumes would no longer be ensured. This problem is especially avoided, if a gripping device is assigned to each guide bar ensuring that the curtain cannot slide out of the bars.
The end bar common to at least two curtain webs, whose surfaces face each other, prevents a relative movement of the webs under the air current of a blaze and results in a good guidance uniformly tightening both webs. Additionally, the advantage of a seal between the webs is achieved which opens up further possibility of fire protection, as will be discussed below.
By the an intermediate support, bending of coil cores, in particular of those of great length, is avoided. In this way, optionally the necessity of providing a connection between adjacent strips of web is dispensed. Moreover, one can take advantage of a single drive.